select dept_no,
    s.emp_no,
    salary
from dept_emp e left join salaries s on e.emp_no=s.emp_no 
where (dept_no,salary) in (
    select dept_no,max(salary) 
    from dept_emp e1 left join salaries s1 
        on e1.emp_no=s1.emp_no 
        group by dept_no
    )
order by 
    dept_no ASC;